Points of sale at a retail location may use a combination scanner and scale to both weigh items (e.g., produce) and scan bar codes on merchandise for sale. Using a laser or imaging device in both horizontal and vertical windows of the scanner, the user (e.g., clerk, consumer) can move the merchandise past one or more of the windows to read the bar code printed on the exterior of the merchandise and reflect back to a light sensor. If one is purchasing something by weight instead of a bar code, the user places the merchandise on the scale that provides a measured weight to a controller. The user can then input a price per pound into the controller using a keyboard or keypad for the controller to generate a total price for the item.
Most jurisdictions require the retail scales to be calibrated in order to ensure that their measured weights are accurate and consistent. The calibration may require special equipment and/or authorized (e.g., licensed) technicians to perform the calibration. Whenever the scanner requires servicing, the scanner and scale unit is removed from the point of sale system in order to repair or replace faulty printed circuit boards or perform any other repairs. Whenever the scale is removed from the system, it should be recalibrated prior to being used again. This results in an expense and down time for the retailer to not only repair the system and pay for recalibration but the point of sale system is out of commission while waiting for an authorized technician to perform the recalibration.